Debris may be present in the oil within an engine during engine assembly. The debris may enter the engine from the external environment or from machining during engine manufacturing. For example, metal flakes and other debris produced during manufacturing of engine lubrication passages and other engine parts may enter the oil. Some engine lubrication systems are structured such that the debris may pass through various components such as cam phasers, valve adjusters (e.g., lash adjusters), bearings, tensioners, pistons, etc., before entering an oil filter where the debris may be removed from the oil. Therefore, during start-up of a “green” or new engine, unfiltered oil that includes debris may flow into the aforementioned components. As a result, the engine components may degrade, and the degraded components may degrade operation of the engine. An example of an engine lubrication system including a cam phaser positioned downstream of an oil filter and an oil pump is described in U.S. Patent Publication No. 2005/0061289.
The inventors herein have recognized the above-mentioned disadvantages of a closed lubrication system and have developed an engine lubrication system, comprising an engine block including an oil gallery passage extending through the engine block and supplying oil to a group of one or more moveable engine components, the oil gallery passage supplied oil from an oil pump, the oil gallery passage in fluidic communication with a drainage passage, and a movable stopper positioned in the drainage passage that selectively bypasses oil from the oil pump to an oil reservoir.
By bypassing engine oil around hydraulically operated devices and lubricated components of an engine before an engine is first operated, it may be possible to reduce engine component degradation. Specifically, the bypassed engine oil can be returned to an oil reservoir with the debris, and the debris can be filtered from the oil before the oil is used to lubricate engine components and operate hydraulic actuators. After debris is flushed from engine lubricating passages, the oil bypass passages may be closed so that oil is directed to engine components and hydraulically actuated devices.
The present description may provide several advantages. Specifically, the approach may reduce engine component degradation by allowing debris to be removed from engine oil before the engine oil passes through the components being lubricated. Further, the approach allows debris to be flushed from the interior of an engine without having to remove cylinder heads or crankshaft components. Further still, the approach provides quick access to engine oil passage flow regulating devices so that once the debris is flushed from oil passages, oil can be directed to engine components for lubrication and activation.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.